Screw-thread cutter.



PATENTED APR. 17, 1906.

L. A. WESTMAN.

SCREW THREAD CUTTER.

APPLICATION FILED MAR.2B, 1904.

2 8HEETS-SHEIIT 1.

IN VENTOI? M ATTORNEYS PATENTED APR. 17, 1906.

. L. A. WESTMAN.

SCREW THREAD CUTTER.

APPLICATION FILED MAR.28, 1904.

2 SHEETS-SHEET 2-.

PATENT ()FFIG.

LEROY A. WESTMAN, or CLEVELAND, OHIO.

SCREW-THREAD CUTTER.

Specification of Letters Patent.

Patented April 17, 1906.

Application filed March 28.19%. Serial No. 20am.

To ooZZ whom it may concern:

Be it known that I, LEROY A. WESTMAN, a citizen of the United States of America, residing at Cleveland, in the county of Guyahoga and State of Ohio, have invented certain new and useful Improvements in Screw- Thread Cutters and I hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use the same.

This invention relates to improvements in screw-thread cutters.

The object of this invention is to provide a screw-thread cutter having a stock composed of two sections relatively adjustable to increase or decrease the space between them, which stock is provided with a plurality of pairs of cooperating screw thread cutting dies, with the dies of each pair of cooperating dies formed upon different rotatable disks, respectively, with one of the said disks carried by the slidable section of the stock of the thread-cutter, with the said slidable stocksection engaging parallel slideway-forming members projecting from and rigid with the relatively stationary section of the stock, and with means for preventing rotation of the aforesaid disks.

Another object is to provide a thread-cutter of the character indicated which is simple and durable in construction and convenient.

With these objects in view, and to the end of realizing other advantages hereinafter appearing, this invention consists in certain features of construction and combinations of parts hereinafter described, and pointed out in the claims.

In the accompanying drawings, Figure 1 is a face view of a screw-thread cutter embodying my invention, and portions are broken away and in section in this figure to more clearly show certain features of construction. Fig. 2 is an elevation largely in central horizontal section on line 2 2, Fig. 1, looking in the direction indicated by the arrow, except that in Fig. 2 my improved thread-cutter is shown being applied to the pipe or work to be screw-threaded. Fig. 3 is a view opposite to the view shown in Fig. 1. Fig. 4 is a vertical section on line 4 4, Fig. 2, looking in thedirection indicated by the arrow. Fig. 5 is a section in detail, showing a nut R, engaged by the tooth or projecting member t of the spring-catch T.

Referring to the drawings, A and B designate the two sections of the stock of my improved thread-cutter. The stock-sections A and B substantially correspond in construction and dimensions. The stock-section B is shiftable or adjustable toward and from the relatively stationary stock-section A, as will hereinafter more clearly appear.

Each stock-section is provided mteriorly with a chamber 0, having the dimensions required to accommodate the location therein of a die-bearing disk D, which is tightly driven upon or otherwise operatively connected with a pin or axle G, which extends transversely through the respective stocksection and has bearing in the side walls of the interior chamber 0 of the said stock-section and is arranged perpendicularly to the path of the slidable stock-section B. Each axle G is provided at the outer side of one of the side Walls of the chamber C, through which the said axle extends, with a head or collar g, abutting against the saidside of the said wall, and the said axle extends a suitable distance beyond the outer side of the other side wall of the said chamber C, and a disk H is tightly driven upon or otherwise 0 eratively connected with the said axle at t e said side of the last -mentioned wall. Each axle G is operatively provided, therefore, externally of the stock-section through which the said axle extends with a disk H, and the said axle extends through and a suitable distance beyond the outer face of the said disk and is reduced diametrically and screw-threaded externally, as at 12, at the said face of the said disk, and a correspondingly-threaded nut K is mounted upon the said threaded end portion of the said axle, and a washer is is interposed between the said nut and the adjacent disk. By the construction hereinbefore described it will be observed that the hGELClS g of the axles G and the nuts K on the axles prevent endwise displacement of the axles.

Each die-bearing disk D is provided with a plurality of screw-thread-cutting dies varying in size. Each disk D has in the device illustrated three thread cutting dies d, formed at the periphery of the said disk equidistantly circumferentially of the disk. The thread-cutting dies (1 of each disk D corre spond and are adapted to cooperate with the different dies, respectively, of the other disk D and the cooperating dies of any pair of dies are brought into an operative position upon 1 turning the said disks to bring the said dies 5 is to be cut is placed and held in 50 other.

opposite each other between the inner ends of the stock-sections A and B. The pipe or rod or work w (shown in Figs. 2 and 4) and upon and exteriorly of which a screw-thread position in any approved manner.

The disks D are upon their adjustment to render operative the pair of cooperating dies required in cutting a given screw-thread I locked against rotation, as will hereinafter more clearly appear, so that the said disks cannot turn during the operation of the said dies. Fig. 1 of the drawings shows the medium-sized pair of dies of the disks D in po- 1 5 sition for operation; but obviously the stocksection B is adjusted toward or from the relatively stationary stock-section A upon relatively readjusting the said disks according as the smaller dies or the larger dies are to be brought into position for operation.

Improved means employed in adjusting the stock-section B toward and from the stock-section A to decrease or increase the space between the said stock-sections com- 2 5 prises two parallel studs L, rigid with and projecting from the stock-section A at opposite sides, respectively, of the work-receiving space between the two stock-sections into and through the stock-section B. The said studs L extend loosely through correspondingly-arranged holes 1), formed in and extending through the stock-section B, as shown in dotted lines, Figs. 1 and 3. Correspondingly-threaded nuts R are mounted on the studs L at and abut against the inner ends of the stock-sections B and shift the said stock-section outwardly away from the stock-section A or permit the stock-section B to be adjusted inwardly toward the stock- 4 section A, according as the nuts R are turned in the one or the other direction. Correspondingly threaded thumb nuts J are mounted upon the studs L at and abut against the outer end of the stock-section B and are instrumental in tightening the said stockthat the studs L form slideways for the slideforming stock-section B.

Means for preventing accidental turning of the nut R on one of the studs L is provided and comprises, preferably, a springcatch T, which is rigidly secured at one end to the stationary stock-section A and extends to and a suitable distance over and closely overlaps the shiftable stock-section B. The spring-catch T is arranged adjacent the re spective nut R, which is provided in its periphery with grooves 7", extending longitudinally of the nut and arran ed at suitable intervals circumferentially of the nut with one of the said grooves normally engaged by a tooth or projecting member t, with which the spring-catch T is provided, as shown in Fi s. 4 and 5. The spring-catch T is preferably arranged at the inner side of the respective nut R, where the said catch is out of the way, and the nut-engaging member t is formed, preferably, upon, an. arm 15 of the said catch, which arm extends inwardly be tween the stock-sections A and B at the aforesaid side of the said nut. The catch T is provided at its free end (see Fig. 1) with a pointer 13, which cooperates with a series of graduations or scale 14, which is marked upon the face of the stock-section B and parallel with the studs L in indicating the distance apart of the two stock-sections A and B. The drawings illustrate the medium sized dies of my improved screw-thread cutter in position for operation, and the pointer 13 is arranged midway between the ends of the scale 14 to indicate that the two stocksections are accurately adjusted relative to each other preparatory to the operation of the said dies. The grooves r in the nut R, which is engaged by the tooth or member t of the spring-catch, are V-shaped transversely, so asnot to interfere with the manual turning of the said nut.

The die-bearing disks D having been accurately adjusted to bring the dies thereof which are next to be operated in position for operation are locked against rotation. Each stock-section is provided with an endwiseadjustable pin P, which is arranged parallelly with the axle G of the disk D, arranged within the said stock-section, and is located centrally of the outer end of the said stocksection. The said pin P is provided at the face and externally of the said stock-section with a head 16 and is cylindrical, externallyscrew-threaded, and reduced diametrically at its opposite end, as at 17, and the said pin is gradually increased diametrically from its end portion 17 toward its head 16that.is, the said pin P tapers from its head 16 toward its screw-threaded end 17, which extends externally of the stock-section through which the said pin extends. The said pin has its tapering portion snugly fitting a hole which is formed partially in the surrounding wall of the chamber C of the said stock-section, as at 20, and partially in the periphery of the respective disk D, as at 22. The disk D of each stock-section is provided in its periphery with as many recesses 22 as there are dies formed on the said disk, which recesses alternate with the said dies, and the arrangement of the said dies and recesses is such that in the operative position of any one of the said dies one of the said recesses 22 shall be in registry with the recess 20 in the surrounding ioo wall or the chamber in the stocksection that is, the arrangement of the parts is such the said disk is in an operative position.

The disks H guide and afford bearing to the object or work w to be screw-threaded preparatory to and during the thread-cutting operation upon the work, and each disk H is provided in its periphery with as many bearing-forming work-guiding recesses h as there are dies on the disk D, operatively connected and arranged coincident with the said workguiding disk H, which recesses vary in dimensions. Each disk H in the device illustrated is provided, therefore, with three recesses h, varying in size and arranged at suitable intervals circumferentially of the disk, and the arrangement of the parts is such that when the pair of medium-sized dies cl of the disk D are in an operative position, as illustrated in Fig. 1, the pair of medium-sized cooperating recesses h are in an operative position, as shown in Fig. 3.

Each disk H of each stock-section is also provided in its periphery with as many recesses 23 as there are recesses it formed in the said disk, and the recesses 23 and the recesses h alternate, and the relative arrangement of the said recesses h and 23 corresponds with the relative arrangement of the dies (1 and the recesses 22 of the disk D, which is operatively connected with the said disk Hthat is, the arrangement of the parts is such that the wall of a recess or hole It in each disk H shall be in position to aflord bearing for the object or work w to be screw-threaded when the dies which are to operate upon the said Work are in an operative position. The recesses or holes 23 are screw-threaded to render them capable of receiving the correspondingly-screw-threaded ends 17 of the pins P. The pins P are screwed into the respective recesses or holes 23 in the disks H to positively lock the said disks in the desired adjustment.

Of course the pins P are withdrawn from the engaging recesses or holes 23 in the disks H and from the enga ing recesses or holes 22 in the disks D to ren er the said disks H and D free to be turned, and thereby readjusted;

but the said pins are again shifted into the said disks as required'to lock the latter upon the readjustment oi the disks.

It will be observed also that the engagement of the screw-threaded ends 17 of the pins P with the screw-threaded holes 23 of the disks H in the operative position of the disks D prevents accidental withdrawal of the said pins from within the said disks D.

Each stock-section is provided at its outer end and centrally with an outwardly-projecting arm 25, which is arranged parallelly with the studs L. The arms 25 serve as handles in the manual manipulation of the threadcutter.

What I claim is- 1. In a screw-thread cutter, the combination, With the stock, two turnable cooperating die-bearin disks supported from the stock and provi ed each with screw-thread-cutting dies arranged at suitable intervals circumferentially of the respective disk, and two workguiding disks connected with the different die-bearing disks respectively, of movable pins adapted to extend from within the diebearing disks through the stock into the work-guiding disks, which pins are in an operative or inoperative position according as they extend into or are withdrawn from the disks.

2. A screw-thread cutter comprising a stock; two turnable cooperating die-bearing disks supported from the stock and provided each with screw-thread-cutting dies spaced circumferentially of the respective disk; two working guiding disks connected with the different die-bearing disks respectively and provided with screw-threaded holes, two correspondingly-threaded removable or withdrawable pins arranged and adapted to eX- tend through the different die-bearing disks respectively through the stock and screw into one of the aforesaid holes in the workguiding disk connected with the respective die-bearing disk.

In testimony whereof I sign the foregoing specification, in the presence of two Witnesses, 19th day of March, 1904, at Cleveland,

LEROY A. WESTMAN.

Witnesses C. H. DORER, G. M. HAYES. 

